Create a copy while the list is visible
Open My List and select Create backup. Copy all the text from the backup box into a note you control. Keeping only a few title lines will not preserve the importable format.
Merge into another browser
Paste the complete text into Restore backup and select Merge backup. Recognised titles are added without removing titles already saved there. Existing checkpoints in the receiving browser take precedence.
What a backup cannot recover
It cannot retrieve a list from a closed website, a different brand's account or browser data you already erased. If you still have a handwritten list, search those productions and save them again.
Read the import message
Malformed text is rejected. Unknown catalogue references or invalid episode reminders can be skipped, and a backup marked for another brand is not accepted. The message explains the result so you can inspect the saved list afterwards.